Means for regulating the passage of gases in heat exchangers



April 24, 1945. D. DAMN 2,374,178

'MEANS FOR REGLATINGI THE PASSAGE OF GASES IN HEAT EXGHANGERS 2l y n /524 April 24, 1945.- D. DALIN 2,374,178 MEANS FOR REGULTING THE PAS-SAGEOF GASES IN HEAT EXCHANGERS `Fled Dec. l2, 1942 2 Sheets-Sheet 2Parc-nica Apr. 24, A19.45

MEANS FOR REGULATING THE PASSAGE F GASES IN HEAT EXCHAN GERS Davia Daun,sccicrtclje, sweden Application Dcccmbcr 12, 1942,'scria1 Nc. 468,832 InSweden September 16, 1941 v 7 Claims.

invention relates to heat exchange apparatus and-.refersparticularly toa shutter or damper construction for controlling the flow` oftemperature modifying gases through a gas pass in which a heat exchangermay be located.

There are many instances .in heat exchange apparatus where it isdesirable to regulate the flow of hot gases-through a gas pass andthereby control the effect of the hot'l vgases upon a heat exchangerwhich may be a superheater or the like. One such instance is found insteam generators wherein the furnace has an oiltake gas passage in whicha superheater is located. Thus, by controlling the amount of the hotgases which pass through that portion ofthe oitake gas pasisage in whichthe superheater is located a predetermined output condition may bemaintained for the steam generator.

With this general objective in view, it is an object of the presentinvention to provide a shutter or damper construction for controllingthe passage of gases through an opening and wherein the shutter ordamper comprises a bank of fluid cooled tubes certain of which aremovable with respect to others to vary the spacingl between the f' tubesand thereby regulate the flow of gases through the opening. f y

More specifically, it is an object of this invert l .tion to provide aheat exchange` I apparatus quibpdwith cooperating walls whichfderi pri`c marf'yzandsecondary gas passagesconnectedfby a.

inlet and a by-pass opening. and wherein a bank of liuid--cooled tubesextending-across the by-pass opening serves to regulatev the liow` ofhot gases-through that portionyof the secondary ypassage lying betweenthemain inlet and the .iacent'tubes and thereby determine theeffectivenation and arrangement, of parts substantial]y as hereinafterdescribed and more particularly.v defined by the appended claims, itbeing under' stood that suchV changes in the precise embodiment of thehereindisclosed invention may be made as come within the scope of theclaims.

The accompanying drawings illustrate one complete example of thephysical embodiment of the inventionconstructed according to the bestmode so far devised for the practical application of the principlesthereof, and in which:

Figure 1 is a vertical-sectional view through a steam generatorillustratingI one application of Figure 5 is a-vicw simuar'tc Figure a,but shcwflexed to vary their positions with respect to adness of thebarrier formed by the b'anli of tubes.

The present invention is particularly advantageous in the control of gasflow through separate'passageways of thev furnace chamber in a steamgenerator for the reason that one set of tubes may be used` to form thevariable shutter or damper and also line the furnace walls tosimultaneously insulate the furnace walls and constitute part of theboiler heatjexchange surface.

Withthe above and other objects in view, which will appear as thedescription proceeds, this invention resides in the novel construction,combithe invention;

Figure 2 is an enlarged view showing a portion .taken Ithrough Figure 2on the plane of the line 3-3 and showing the open and closed positionsof the damper; and' ing a slightly modified arrangement of the tubes.

`Referring now particularly to the accompanyink drawings in which likenumerals indicate like parts, the numeral 5' designates a partition wallwhich cooperates with fixed furnace walls 6, 1, and' to form a primarygas passageway 9 and a secondary gas passageway I0, the furnace walls'having a refractory lining I I.

, me tcp cf the partition wan s is spaced frc'ncy the top furnace wall 1to provide a main'inlet opening I2 'connecting the primary and secondarygas passageways at the top. A by-pass opening I3 in the partition walland spaced downwardly from the top thereof provides another point ofcommunication between. the two passageways.

The area of the secondary passageway III lying y between the main inletopening f I2 and the bypass opening I3 constitutes a heating chamber Ilin which a superheater I5 is located.

The inlet 'ends .of the superheater coils are connected with an inletheader I6 which in turn is connected to a steam drum I1 by a. supplyline.'

partition wall `5. The tubes or coils then con I tinue across thesecondary gas passageway tol a point adjacent to the top of thepartition wall where they are directed abruptly upwardly and downwardlyto form hairpin bends 22 and continue downwardly across 4the face of thepartition wall defining one side of the primary gas pas- I SageWaY,

Adjacent tubes or coils have their hairpin portions 22 oilset so as topermit the flow of combustion gases through the main inlet opening I2,the extent of the odsetl determining the freedom of gas flow through themain inlet.

At the by-pass opening I3 the tubes or coils are disposed inside by siderelation to normally close the by-pass opening so that the gases enterthe secondary gas passageway into openings 24 in` the wall 8 where theyare looped back on themselves as at 25. The loops 25 havelinks 26connected thereto and extended out through the wall 8 to provide meansfor applying endwise motion to the looped portions of the coils.

The mechanism by which-such motion may be imparted to the coilscomprises a shaft 21 mounted for oscillation and providedwith levers 28which have their free ends connected to the links 26. A gear-segment 29secured to the shaft 21 meshes with a pinion 29' driven from a Selsyntype motor 3l by a worm and worm wheel 3|. A coveror housing 32preferably encloses the projecting ends of the links and their actuatinglevers to close the openings 24.

The Selsyn type/motor is controlled by an impulse organ or regulatingmechanism Il responsive to temperature sensitive control means (notshown) but governed by the temperature of the steam issuing from thesuperheater, the im pulse organ acting through a relay 2l.

Upon oscillation of the shaft 21 either by the Selsyn type motor or by amanually actuatable handle 35 allof the levers Il and all of the coilsdriven thereby are pushed or pulled to flex the tubes so connectedthereto and extending across the by-pass opening to vary their spacingwith relation to the other stationary tubes which continue straightacross the by-pass opening. Thus, it is possible to adjust the size ofthe bypass opening to permit the hot combustion gases to by-pass thesuperheater coils andV thereby maintain a predetermined temperaturecondition for the steam issuing from the superheater.

It is, of course, obvious that the levers It can be mounted on the shaft21 in different positions of angular relationship so that certain of thecoils will lbe moved farther than others if this is found desirable ornecessary to maintain proper control for the flow oi' hot gases or forlike purposes the links may have a lost motion connection with theirrespective levers 2l.

The tubes or coils 2l are adapted t6 have a suitable coolant, as forinstance. a water-steam emulsion, continuously circulateds therethroughand as will be readily apparent, the tubes, or coils may'constitute partof the heat exchange surface .of the boiler. Therefore, they not onlyserve the dual function of increasing the heating surface of the boilerand of providing a controllable damperor shutter for the by-pass'opening I3, but, lining the wallsofthe furnace chamber as these wallsfrom direct said partition wall having a main opening through which saidpassageways are connected for the flow of hot gases from the primarypassageway into the secondary passageway and having a bypass openingspaced from the main opening through which thehot combustion gases mayflow to avoid the area inthe secondary passageway lying between saidopenings; a heat exchange device in said area of the secondarypassageway; a bank of fluid cooled tubes extending across said bypassopening to form a barrier of variable eiectiveness depending upon thespacing' of said tubes, said tubes extending along the partition wall toa point spaced a considerable distance from the bypass opening, certainof the tubes having their portions which extend across the bypassopening movable with respect to the other tubes by flexure of theirportions remote from the bypass opening; and means connected to saidmovable tubes for flexing said tubes to vary the effectiveness of thebarrier across the bypass opening. and consequently the ailect of thehot combustion gases on the heat exchange device. Y

2.- In a heat exchange apparatus: fixed iurnace walls; a partition wallcooperating with said ixed furnace walls to define adjacent primary andsecondary passageways for hot combustion gases, vsaid partition wallhaving a main opening through which said passageway/s are connectedi'or` the iiow of hot gases from the primary passageway into thesecondary passageway and having a bypass opening spaced from the mainopening through which the hot combustion gases may flow to avoid thearea in the secondary passageway lying between said openings; a heatexchange device in said area of the secondary passageway; a bank offluid cooled tubes extending across said bypass opening to form abarrier of variable effectiveness depending upon the spacing of saidtubes, the tubes of said bank extending across the partition wallbetween its two openings and across the main opening where they have areverse bend, the spacing of the tube portions extending across the mainopening-being substantial so as not to interfere too greatly with theflow of gases from the primary passageway into the secondary passageway,the portions of 'the tubes extending across the bypass opening beingnormally closely adjacentto each other to -form an effective barrier;and means connected `to certain of the tubes at the bypass opening'forflexing said tubes from their reverse bends to alter the spacing betweenthe tube portions extending across the bypass opening and thus vary theeffectiveness of the barrier across the bypass opening andcorrespondingly alter the affect of the hot combustion gases on the heatexchanger.

3. Inga heat exchange apparatus: fixed furnace walls; a partition wallcooperating with said fixed furnace walls to deilne adjacent primaryaaraifia opening to line part o the walls of the secondary passageway,said tubes also extending across the partition wall space interveningits openings, and

certain of the tubes having continuations thereof passing through thebypass opening and extending across the secondary passageway to a pointadjacent to one of the fixed furnace walls; and means on the exterior ofsaid xed furnace wall and connected to said adjacent tube portions formoving said portions toward and from the partition wall so as to ex thetubes'connected thereto and thus shift the-same relative to the othertubes extending across the bypass opening to vary the effectiveness ofthe barrier across said bypass opening.

4. In a heat exchange apparatus of the character described; cooperatingiixed walls denning a passageway for hot combustion gases, saidpassageway having an inlet through which hot combustion gases normallyenter the same, one of the walls defining said passageway having a,bypass opening through which the hot gases may flow into the passagewayand thus bypass that 4 part ci the passageway lying between the bypassopening and the inlet; a bank of uid cooled tubes overlying said walland extending across the by-pass opening, said tubes in their normalpositions being closely adjacent to substantially close the bypassopening, certain of the tubes being bent abruptly and extending throughthe bypass opening across the passageway to the opposite wall thereof atwhich point said tubes have a return bend to again cross the passagewayand extend through said bypass opening; and means exteriorly of saidpassageway and connected to the reversely bent portions of the tubes forshifting the same toward and from the wall in which4 the bypass openingis located to thereby hex the tubes connected thereto out of theirnormal positions `to vary the spacing between vthe tubes forming thebarrier across the bypass opening.

5. In a heat exchange apparatus of the character described: fixedfurnace walls; kan upright, partition wall cooperating with the' furnacewalls to dene substantially vertical primary and secondary passagewaysfor-hot Acombustion gases, the top of said partition wall being spacedfrom the top fixed furnace wall to provide normal communication betweensaid passageways, said partition wall having a bypass opening spaceddownwardly oi' its top, the space in the secondary passageway betweenthe top of the partition wall and its bypass opening serving asasuperheater chamber; a superheater in said chamber; a bank oi fluidcooled tubes covering the upper portion of the partition wall andextending across the bypass opening to form a barrier of variableeiectiveness depending upon the spacing of the tubes, certain of saidtubes being movable at least in their portions which extend across thebypass opening to varythe eiectiveness of said barrier, said movabletubes having lop portions extending through the bypass opening andacross vthe secondary passageway to a 'point adjacent to 'tubesandlthereby vary the effectiveness oi the barrier and correspondinglyalter the affect of the hot combustion gases on the superheater.

6. In a heat exchange apparatus of the character described: ixed furnacewalls; an upright partition wall cooperating with thev furnace walls todefine substantially Vertical-primary and secondary passageways for hotcombustion gases, the top of said partition wall being spaced from thetop fixed furnace wall to provide normal cornrnunication between saidpassageways, said partition wall having a bypass opening spaceddownwardly of its top, the space in the secondary passageway between thetop of the partition wall and its bypass opening serving as asuperheater chamber; a superheater in said chamber; a bank of fluidcooled tubes covering the upper portion of the partition wall andextending across the bypass opening to form e, barrier of variableeii'ectiveness depending upon the spacing of the tubes, certain of saidtubes being movable at least in their portions which extend Aacross thebypass opening to vary the effectiveness of said barrier, said movabletubes having loop portions extending through the bypass opening andacross the secondary passageway to apoint adjacent to the opposite fixedfurnace wall; and means exteriorly of said fixed furnace wall andconnected with said looped portions for shifting said looped portionstoward and from the partition wail to shift -the partition wall beingspaced to permit4 the iiow of hot combustion gases therebetween.

7. In a heat exchange apparatus: fixed furnace walls; an uprightpartition wall cooperating with the furnace walls to define adjacentprimary and secondary passageways; af main opening connecting -theprimary and secondary passageways; said partitiouwall having a bypassopening at a distancerom said main opening through which hot combustiongases flowing in the primary passageway towards themain opening mayenter the secondary passageway before they reach the main opening andthus bypass the space in the secondary passageway beyond the bypassopening; a superheater in said space; a bank of liquid cooled tubesconnected'to'a source of cooling liquid and extending across the bypassopening and by their spacing controlling the amount vof hot gases whichbypass-the superheater in the secondary passageway beyond the bypassopening; and'means connected to certain of said tubes in the region ofthe bypass opening for exing said tubes to shiftitheir portions whichextend across the bypass opening with respect to the remaining tubes andthus vary the spacing between the tubes to control the amount of the hotgases which bypass the superheater.

DAVID DALIN.

